Coetzee, Rigardt Alfred, Aggrey Mwesigye, and Zhongjie Huan. “Optimal Slope Angle Selection of an Evacuated Tube Collector for Domestic Solar Water Heating”. Journal of Energy in Southern Africa 28, no. 1 (March 23, 2017): 104–119. Accessed April 19, 2024. https://energyjournal.africa/article/view/1621.